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____ The exon theory of genes states that genomes consist solely of exons. introns are deleterious and are purged from the genome. introns lead to recombination errors. many current genes arose through the rearrangement of exons into new combinations. _____ Which of the following is NOT a reason why the twofold cost of sex is sometimes referred to as the “cost of males”? Males do not contribute genes to the next generation. Males do not produce new offspring. Males invest in sperm, most of which are wasted, rather than biomass. Sperm cells do not contribute any substantial energy resources to the eggs they fertilize. ____ The two figures represent an asexual and a sexual population. The letters indicate beneficial mutations. The shaded areas represent the frequency of particular combinations of mutations in the population over time. Why does it take longer for the beneficial allele combination of ABC to go to fixation in the asexual population than in the sexual population? In the asexual population, new allelic combinations have to arise via de novo mutations. There is no principal difference between asexual and sexual populations. In the sexual population shown, the favorable mutations just happen to be on different chromosomes. The effective population size of both populations is the same. Sexual populations tend to have higher mutation rates. _____ Why is male reproductive success limited by the number of eggs? Sperm are short lived compared to eggs and it is more expensive for males to reproduce because males produce a much greater number of gametes than three are eggs available to fertilize. Eggs are much larger and scarcer than sperm, limiting the number of opportunities for reproductive success for males. Eggs are smaller than sperm and short lived, limiting the number of opportunities for reproductive success for males. Although eggs are not metabolically expensive to produce, most female organisms will only produce a small number of eggs during their life span.